Mercedes' new record for global sales in a single month -- 158,523 cars and SUVs -- probably won't last long.

With the new-generation C class, Mercedes' No. 1 seller globally, and the all-new GLA SUV starting to arrive at dealers now, the German automaker is poised to surpass the high-water mark set in March as early as this month.

Continued strong demand for its other compacts -- the CLA, B class and A class -- likely will help Mercedes continually reset its single-month sales record during the course of this year.

The volume surge also could boost No. 3 Mercedes in the global ranking of top-selling premium carmakers. Why? Because second-ranked Audi's biggest car launch this year will be the third-generation TT, which is not a high-volume model.